1. Field of the Invention
The present invention relates to an aberration corrector equipped with a multipole and a charged particle beam apparatus using the above-mentioned aberration corrector.
2. Description of the Related Art
In a microscope, a micromachining apparatus, a semiconductor manufacturing apparatus and so forth configured by practically applying charged particle beams, single-stage or multi-stage multipoles (dipoles, quadrupoles, hexapoles, octupoles and so forth) are used in a deflector and an abberation corrector of beams. Recently, machining with acuracy of about 10 nanometer order or abservation with accuracy of sub-nanometer order is performed by using the above-mentioned apparatuses in which the charged particle beams are practically applied and it is desired to control the beams with accuracy of sub-nanometer order. In the deflector and the aberration corrector to be incorporated into the above-mentioned apparatuses in order to implement such control, although, naturally, final adjustment is electrically performed, it is necessary to assemble the multipole with high machine accuracy as a precondition. Hitherto, as a technique for forming the multipole with accuracy, for example, Japanese Patent Application Laid-Open No. H11-339709 discloses a technique that in manufacture of the multipole, a positioning member is set on an optical axis, a pole is pressed against and fixed to the positioning member, and thereafter the positioning member is drawn out. Japanese Patent Application Laid-Open No. H5-334979 discloses a system that a ball-shaped or cylinder-shaped spacer is arranged in a cylindrical housing to position the multiple. Japanese Patent Application Laid-Open No. 2004-241190 discloses a system of fixing individual poles to a base plate with pins and a technique of fixing an integrated pole member and thereafter cutting off each pole by a wire cutter. Japanese Patent Application Laid-Open No. 2009-43533 discloses a system of fixing a multi-stage coupled pole to a base block. Japanese Patent Application Laid-Open No. 2006-139958 discloses a system of forming an electrostatic multipole by using a metal layer disposed on an inner wall of a cylindrical-shape type ceramic cylinder as an electrode. Japanese Patent Application Laid-Open No. 2012-209130 discloses a technology of forming a multipole by fitting a pole member that includes a pole, a support member such as a support and so forth into a groove provided in a cylindrical housing having a through-hole through which charged particles would pass and disposed in parallel with an optical axis direction and then fixing the pole member. Japanese Patent Application laid-Open No. 2007-287365 discloses a technique of bringing a terminus of a pole that configures a magnetic path and a tip of an iron core member into contact with each other with a spacer interposed between the pole and the iron core member.